In the case of an incoming WS-AT transaction, this mapping is keyed on the transaction ID of the WS-AT transaction with an association to the JTA XID. The format of XID used here is BridgeDurableParticipant rather than JTA. Two reasons for this are; 1) it helps to distinguish record types at recovery time and B) it prevents branching, which cannot be done in this scenario due to a limitation in JC